Hanaya Yohei is generally credited as the inventor of today's Tokyo-style ("Edo-mae"; 江戸前) "nigiri" sushi (hand-formed sushi) at the end of Japan's Edo period. Sushi at his time was made from freshly captured fish from the nearby Tokyo Bay. This ruled out many of today's popular materials such as salmon roe ("ikura"; イクラ). Even though Tokyo is a coastal city, food safety was still a concern before the invention of refrigeration. Wikipedia
The definitive Wikipedia entry for Hanaya Yohei. Wikipedia is the biggest multilingual free-content encyclopedia on the Internet. en.wikipedia.org/wiki/Hanaya_Yohei
